Chiffchaff
The Chiffchaff (Phylloscopus collybita), is a common and widespread leaf-warbler which breeds in open woodlands throughout northern and temperate Europe and Asia. It is a migratory passerine (song bird) which winters in southern and western Europe, southern Asia and north Africa. Greenish-brown above and off-white below, it is named onomatopoeically for its simple chiff-chaff song. It has a number of subspecies, some of which are now treated as full species. The female builds a domed nest on or near the ground, and assumes most of the responsibility for brooding and feeding the chicks, whilst the male has little involvement in nesting, but defends his territory against rivals, and attacks potential predators. A small insectivorous bird, it is subject to predation by mammals, such as cats and mustelids, and birds. It may also acquire external or internal parasites. Its large range and population mean that its status is secure. Description The Chiffchaff is a small, dumpy, 10–12 centimetres (4 in) long leaf warbler. The male weighs 7–8 grammes (0.28–0.31 oz), and the female 6–7 grammes (0.25–0.28 oz). The spring adult of the western nominate subspecies P. c. collybita has brown-washed dull green upperparts, off-white underparts becoming yellowish on the flanks, and a short whitish supercilium. It has dark legs, a fine dark bill, and short primary projection (extension of the flight feathers beyond the folded wing). As the plumage wears, it gets duller and browner, and the yellow on the flanks tends to be lost, but after the breeding season there is a prolonged complete moult before migration.9 The newly fledged juvenile is browner above than the adult, with yellow-white underparts, but moults about 10 weeks after acquiring its first plumage. After moulting, both the adult and the juvenile have brighter and greener upperparts and a paler supercilium. When not singing, the Chiffchaff can be difficult to distinguish from other leaf warblers with greenish upperparts and whitish underparts, particularly the Willow Warbler. However, that species has a longer primary projection, a sleeker, brighter appearance and generally pale legs. The Chiffchaff also has rounded wings in flight, and a diagnostic tail movement consisting of a dip, then sidewards wag, that distinguishes it from other warblers. Distribution and habitat The Chiffchaff breeds across Europe and Asia east to eastern Siberia and north to about 70oN, with isolated populations in northwest Africa, northern and western Turkey and northwestern Iran. It is migratory, but it is one of the first passerine birds to return to its breeding areas in the spring and among the last to leave in late autumn. When breeding, it is a bird of open woodlands with some taller trees and ground cover for nesting purposes. These trees are typically at least 5 metres (16 ft) high, with undergrowth that is an open, poor to medium mix of grasses, bracken, nettles or similar plants. Its breeding habitat is quite specific, and even near relatives do not share it. In winter, the Chiffchaff uses a wider range of habitats including scrub, and is not so dependent on trees. It is often found near water, unlike the Willow Warbler which tolerates drier habitats. There is an increasing tendency to winter in western Europe well north of the traditional areas, especially in coastal southern England and the mild urban microclimate of London. These overwintering Chiffchaffs include some visitors of the eastern subspecies abietinus and tristis, so they are certainly not all birds which have bred locally, although some undoubtedly are. Behaviour Territory The male Chiffchaff is highly territorial during the breeding season, with a core territory typically 20 metres (66 ft) across, which is fiercely defended against other males. Other small birds may also be attacked. The male is inquisitive and fearless, attacking even dangerous predators like the stoat if they approach the nest, as well as egg-thieves like the Eurasian Jay. His song, given from a favoured prominent vantage point, appears to be used to advertise an established territory and contact the female, rather than as a paternity guard strategy. Beyond the core territory, there is a larger feeding range which is variable in size, but typically ten or more times the area of the breeding territory. It is believed that the female has a larger feeding range than the male. After breeding has finished, this species abandons its territory, and may join small flocks including other warblers prior to migration. Breeding The male Chiffchaff returns to its breeding territory two or three weeks before the female and immediately starts singing to establish ownership and attract a female. When a female is located, the male will use a slow butterfly-like flight as part of the courtship ritual, but once a pair-bond has been established, other females will be driven from the territory. The male has little involvement in the nesting process other than defending the territory. The female's nest is built on or near the ground in a concealed site in brambles, nettles or other dense low vegetation. The domed nest has a side entrance, and is constructed from coarse plant material such as dead leaves and grass, with finer material used on the interior before the addition of a lining of feathers. The typical nest is 12.5 centimetres (5 in) high and 11 centimetres (4 in) across. The clutch is two to seven (normally five or six) cream-coloured eggs which have tiny ruddy, purple or blackish spots and are about 1.5 centimetres (0.6 in) long and 1.2 centimetres (0.5 in) across. They are incubated by the female for 13–14 days before hatching as naked, blind altricial chicks. The female broods and feeds the chicks for another 14–15 days until they fledge. The male rarely participates in feeding, although this sometimes occurs, especially when bad weather limits insect supplies or if the female disappears. After fledging, the young stay in the vicinity of the nest for three to four weeks, and are fed by and roost with the female, although these interactions reduce after approximately the first 14 days. In the north of the range there is only time to raise one brood, due to the short summer, but a second brood is common in central and southern areas. Although pairs stay together during the breeding season and polygamy is uncommon, even if the male and female return to the same site in the following year there is no apparent recognition or fidelity. Interbreeding with other species, other than those formerly considered as subspecies of is rare, but a few examples are known of hybridisation with the Willow Warbler. Such hybrids give mixed songs, but the latter alone is not proof of interspecific breeding. Feeding Like most warblers, this small species is insectivorous, moving restlessly though foliage or briefly hovering. It has been recorded as taking insects, mainly flies, from more than 50 families, along with other small and medium-sized invertebrates. It will take the eggs and larvae of butterflies and moths, particularly those of the Winter Moth. The Chiffchaff has been estimated to require about one-third of its weight in insects daily, and it feeds almost continuously in the autumn to put on extra fat as fuel for the long migration flight. Gallery Summer Migrant.jpg|Distribution of Chiffchaffs in the UK Chiffchaffgord.jpg|Chiffchaff - http://www.flickr.com/photos/gordiesbirdies/ Category:Birds Category:Passerine Category:Vertebrates Category:Chordata Category:Resident Breeding Category:Migrant Category:Phylloscopidae